Some electrical circuits rely on a clock signal for operation. The clock signal can be generated internally, either by the electrical circuit or by another circuit implemented on the same die or within the same package as the electrical circuit, or the clock signal can be received by the electrical circuit from another outside device or component via interconnects coupling the electrical circuit to the outside device. Sometimes, the electrical circuit includes an ability to operate based on both the internally generated clock signal and the clock signal received from an outside device, selectively or programmatically.